Microbial Scout Hypothesis and Microbial Discovery
Microbial Scout Hypothesis and Microbial Discovery
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DOI：
10.1128/aem.07308-11
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发表时间：
2012-05-01
影响因子：
4.4
通讯作者：
Epstein, S. S.
中科院分区：
文献类型：
--
作者：
Buerger, S.;Spoering, A.;Epstein, S. S.
在这项研究中，我们研究了培养实验中菌落出现的时间模式，以及这种模式是否可以优化微生物发现的过程。在一系列长期培养实验中，我们观察到微生物分离株的总数随时间逐渐增加，最终在18个月时菌落计数增加了700倍。传统的想法认为，长期孵育导致培养物收集物中富含生长缓慢或稀有的物种，这些物种可能无法从短期实验中获得，并且可能是新颖的。然而，在我们研究了作为其分离时间的函数的分离株的系统发育新奇后，我们发现两者之间没有相关性。在孵化后期发现新物种或稀有物种的概率与早期分离的物种相匹配。这些结果是特别值得注意的，因为它们的普遍性：观察基本上是相同的海洋和土壤细菌以及孢子形成和非孢子形成。这些发现与休眠细胞随机唤醒的想法一致，从而支持侦察模型。微生物发现的过程是环境微生物和人类微生物组研究的核心。虽然长期孵化似乎并没有增加发现新物种的可能性，但实现这种孵化的技术，即，单细胞培养可能仍然是首选方法。虽然它不一定允许更多的物种从给定的接种物生长，但它最大限度地减少了整体隔离工作和所需的供应。
In this study, we examine the temporal pattern of colony appearance during cultivation experiments, and whether this pattern could inform on optimizing the process of microbial discovery. In a series of long-term cultivation experiments, we observed an expected gradual increase over time of the total number of microbial isolates, culminating in a 700-fold colony count increase at 18 months. Conventional thought suggests that long-term incubations result in a culture collection enriched with species that are slow growing or rare, may be unavailable from short-term experiments, and likely are novel. However, after we examined the phylogenetic novelty of the isolates as a function of the time of their isolation, we found no correlation between the two. The probability of discovering either a new or rare species late in the incubation matched that of species isolated earlier. These outcomes are especially notable because of their generality: observations were essentially identical for marine and soil bacteria as well as for spore formers and non-spore formers. These findings are consistent with the idea of the stochastic awakening of dormant cells, thus lending support to the scout model. The process of microbial discovery is central to the study of environmental microorganisms and the human microbiome. While long-term incubation does not appear to increase the probability of discovering novel species, the technology enabling such incubations, i.e., single-cell cultivation, may still be the method of choice. While it does not necessarily allow more species to grow from a given inoculum, it minimizes the overall isolation effort and supplies needed.